This excerpt taken from the SYT 20-F filed Mar 1, 2006.
Deferred Tax Assets
Tax losses are recognized as deferred tax assets when it becomes probable that they will be utilized. Since its formation, Syngenta has carried out a reorganization of the legal entity structure of the group. This has increased the likelihood that tax losses in certain group subsidiaries will be utilized against future taxable profits. Based on the taxable profit forecasts approved by management, Syngenta considers it is now more likely than not that these tax losses will be recovered. Therefore, as shown in Note 16 below, Syngenta has reduced unrecognized tax losses and has increased deferred tax assets recognized for net operating tax losses. Certain tax losses have also been claimed as offsets to current tax expense, which has been reduced accordingly. However, if forecast profits are reduced by adverse market conditions in the future, or by future restructuring decisions, it may be necessary to write off deferred tax assets. Syngenta is not able to quantify accurately the amount of any
future potential deferred income tax expense which might be recorded as a result. At December 31, 2005, Syngentas balance sheet included deferred tax assets of US$140 million for net operating losses, as disclosed in Note 16 below.